5.108 How to obtain list of files with some extension in folder?

Use FileTools:-ListDirectory

dir_name:="C:/tmp"; 
currentdir(dir_name); #cd to directory 
files_to_process := FileTools:-ListDirectory(dir_name,'all','returnonly'="*.tex"): 
numelems(files_to_process) 
    100
 

In the above, files_to_process is a list of the files in the current folder with extension .tex